Oocyte Retrieval in Summer Linked to Increased Odds of Live Birth

FRIDAY, July 7, 2023 (HealthDay News) -- Oocytes retrieved in the summer and on days with high duration of sunshine hours have increased odds of live birth, according to a study published online July 5 in Human Reproduction.

Sebastian J. Leathersich, M.B.B.S., M.P.H., from King Edward Memorial Hospital in Subiaco, Australia, and colleagues conducted a retrospective cohort study including all frozen embryo transfers performed by a single clinic from January 2013 to December 2021. A total of 3,659 frozen embryo transfers with embryos generated were included from 2,155 IVF cycles in 1,835 patients. The season, temperatures, and measured duration of sunshine at the time of oocyte collection and at the time of frozen embryo transfer were assessed with outcomes.

The researchers found that frozen embryo transfers with oocyte retrieval dates in the summer had increased odds of live birth compared to those with oocyte retrieval dates in the autumn (odds ratio, 1.30), which persisted after adjustment for season at the time of embryo transfer. Increased odds of live birth were seen for a high versus low duration of sunshine hours on the day of oocyte retrieval (highest versus lowest tertile: odds ratio, 1.28). The odds of live birth were not independently affected by temperature on the day of oocyte retrieval. But when the minimum temperature on the day of the embryo transfer was high versus low, the odds of live birth were reduced (odds ratio, 0.82).

"Our study suggests that the best conditions for live births appear to be associated with summer and increased sunshine hours on the day of egg retrieval," Leathersich said in a statement.

Two authors disclosed ties to the pharmaceutical industry.

Abstract/Full Text